An optical sensor arrangement often comprises a photodiode as a light sensor and an analog-to-digital converter. Such a photodiode can be used for ambient light sensing. An ambient light sensor may be buried underneath a dark glass, for example, in mobile phone applications, to create a stylish look. Since an incident light is strongly attenuated by the covering dark glass, an ambient light sensor should obtain a high sensitivity.
Document US 2012/0293472 A1 describes an ambient light sensor. A light detector is coupled to an analog-to-digital converter via a filtering circuitry.